To identify babylon, more importantly, mystery babylon, we need to look at her characteristics.
1. International Trade
It's not just America that is involved in global trading, it is by definition all those coastal sea port/cities around the globe.
Rev 18:17 For in a single hour all this wealth has been laid waste." And all shipmasters and seafaring men, sailors and all whose trade is on the sea, stood far off
Jer 51:49 Babylon must fall for the slain of Israel, just as for Babylon have fallen the slain of all the earth.(A major part of the UK's economy is involved in Arms sales.)
3. Immoral - this applies to mystery babylon.
Rev 18:3 For all nations have drunk the wine of the passion of her sexual immorality, and the kings of the earth have committed immorality with her, and the merchants of the earth have grown rich from the power of her luxurious living."The key here is that mystery babylon is not chaste, she goes with anyone. International finance comes to mind.
4. She resists the gospel of Christ - again, mystery babylon
Rev 18:24 And in her was found the blood of prophets and of saints, and of all who have been slain on earth."
Wherever you find resistance to the gospel of Christ being sanctioned by the authorities (or even local people, work colleagues, management, petty officials, etc, who are lost in the harlot's enticements), you have found mystery babylon. Now that should open your eyes.
To really understand all this requires a spirit of revelation - otherwise you just get freaked by what you are considering. Stay in the Way and you will be kept safe from the harlot's clutches.
Rev 18:1 After this I saw another angel coming down from heaven, having great authority, and the earth was made bright with his glory.Rev 18:2 And he called out with a mighty voice, "Fallen, fallen is Babylon the great! She has become a dwelling place for demons, a haunt for every unclean spirit, a haunt for every unclean bird, a haunt for every unclean and detestable beast.Rev 18:3 For all nations have drunk the wine of the passion of her sexual immorality, and the kings of the earth have committed immorality with her, and the merchants of the earth have grown rich from the power of her luxurious living."
So, in conclusion, perhaps there are different facets to babylon. The jeremiah 51:42 prophecy, the seas coming up on babylon, is perhaps just one facet and may be already entirely fulfilled and be just poetical language. However, the reality of the sea levels rising and endangering coastal cities is real enough as is the growing problem of water supply for many cities.